Abstract
A commercially available portable near-infrared spectrophotometer that works in the short near-infrared wavelength region ([SWR], -1100nm) was employed to nondestructively measure the lipid content, a property closely related to taste, of marine fish. The objective of this study was to evaluate the capacity of two SWR spectrophotometers and a long near-infrared wavelength region ([LWR], 1600-2400nm) photometer to determine the lipid content of both the dorsal muscle of silver seabream (Pagrus major) and the liver of black scraper (Thamnaconus modestus). Spectra that was taken from intact silver seabream using all three instruments was able to be used for lipid screening. Also, good calibration equations for black scraper liver lipids were developed from the spectra of the liver ; these were obtained by dissection using all instruments. The liver of black scraper is typically found on the left side of the body. Although the spectra from the left side of the intact black scraper bodies showed absorption characteristic of liver lipids, the lipid determinations were not as accurate as those obtaining using the spectra of dissected livers. Our results suggest that LWR portable near-infrared spectrophotometers are capable of performing as well as SWR photometers for determining the lipid content of cultured marine fish. Further study to evaluate liver lipids in intact fish is required.
